Friday 2 December 2011 13.40 EST
First published on Friday 2 December 2011 13.40 EST

When it was time to take up her university place to study English, Juliet Kay, 18, felt she could not leave her mother, recently separated from an abusive husband, to care for the three younger children alone. The trauma of the prolonged abuse and a series of house moves prompted by the separation had left the whole family unhappy and living in severe poverty.

Juliet was on the point of returning to a job at McDonald's to support the family financially and stay in the southern English town where they live to help care for the children. She felt guilty about going off to pursue her own life when things were so difficult at home.

She was only persuaded to leave when a support worker from the St Giles Trust children and families project (Cafe) stepped in, offering intensive practical support to her mother, and reassuring Juliet that the family would be able to cope without her.

The St Giles Trust is one of the charities that the Guardian and Observer are supporting in this year's Christmas appeal. It provides a wide range of services, focusing on breaking cycles of offending, crime and disadvantage. It supports prisoners when they leave jail, helping with things such as housing and employment, trying to prevent reoffending. The Cafe project works with the families of offenders and with people who have experienced domestic abuse, recognising they need extra support to prevent the consequences of the abuse or offending from damaging the rest of the family.

In Juliet's case, the charity was concerned that she was going to sacrifice her own prospects in order to continue helping her mother, Cathy, who was battling with housing problems and slipping further into poverty.

Without the assistance of project worker Lucy Wilks, Juliet would almost certainly have abandoned her academic ambitions while Cathy and the rest of the family would have continued to teeter on the brink of homelessness.

Lucy tried to relieve some of the burden of responsibility from Juliet, who then felt free to take up her place at university. "If she hadn't known her mother was supported, she wouldn't have felt able to leave and pursue her own life," Lucy says.

Life remains complicated for the family left at home but, with the help of the charity, things are gradually improving. Cathy doesn't like to portray herself as a victim, so it takes some encouragement before she can be persuaded to describe the difficulties her family has experienced over the past 18 months. She sends her children upstairs and reluctantly begins to explain how, two years ago, her family conformed to a model of conventional stability: she was married, with four happy children and a husband who was in work, paying off the mortgage on the family home.

Beneath the surface, she was stuck in a 12-year-marriage to an abusive husband who wouldn't let her work or give her money. She went without shoes and clothes (borrowing Juliet's when necessary), lived in an unheated home with no fridge, struggled to feed the children properly and was forced to cut contact with her family and friends. When her marriage finally collapsed, she moved out with her children into a private-rented home. Then, because of a sudden fall in the amount of housing benefit she could claim, she had to move for a second time about six weeks ago.

She was unable to get council accommodation and unable to afford private rents, but was unwilling to uproot her children from their schools again to move to an area with cheaper rents. As a result, she is caught in a poverty trap so severe that her benefits are being docked to pay historic utility bills, she is cutting the amount she spends on food to pay down catalogue loans for a washing machine and school uniform, and she is using the weekends when her children stay with their father as an opportunity to save money by not really eating.

Her middle daughter's coat is two years old and too small, but there's no money to replace it; another child is sleeping on a mattress on the floor, because the bed has broken and there's no money for a new one; in the evening, the family sit around a television, which doesn't work, because there's no money to mend it; the house they have moved to (which is more expensive than the housing benefit allowance, causing a shortfall of £125 a month) has no central heating and rotting windows which let in the cold winter air.

The impact of the abuse and the ensuing turmoil on the whole family has been profound, and might have been catastrophic had it not been for the involvement of the charity, which understands the damage that witnessing domestic abuse does to the confidence of children and young people, and is working with Cathy to ensure the children are supported.The organisation works alongside social workers and the probation service to supplement the welfare state, recognising that some of the country's most vulnerable people do require extra support.

The Cafe project usually starts by helping with housing problems, before moving on to other less immediately obvious issues, related to the partner or ex-partner's domestic violence or offending. The charity aims to minimise the trauma to the rest of the family by offering concentrated practical support. The project has supported nearly 600 families in this area and would not be able to run without charitable donations.

The independent voluntary sector analyst organisation New Philanthropy Capital, which helped the Guardian select its Christmas charities, praises the "passion and professionalism" of the charity.

Lucy describes her role as akin to being an old-fashioned social worker. Because she has only a handful of families on her list, she is able to offer more intensive support. Shehas helped Cathy apply for crisis loans and pointed her in the direction of officials at the council who may be able to assist.

Cathy's MP and council housing officials sent letters saying they were sympathetic to her plight, but there was nothing they could do to help. By contrast,St Giles offered practical support, raising £800 for the family to fund part of the rental deposit on a new house and offering Cathy a grant to help her buy a second-hand bed frame so her daughter no longer sleeps on the floor.

By keeping the family in stable accommodation, the stress on the children is reduced, the damage to their education is minimised and the charity is able to help avert lasting damage.

The prolonged experience of domestic violence had shattered Cathy's confidence as a parent; she was concerned that the children had witnessed physical and emotional abuse over the years and worried about the possible impact on them. The charity sees its work with younger children as a vital form of early intervention, tackling problems when they emerge, to avert more serious issues later in life.

"If mum hadn't had Lucy there helping her, there's no way I would have come to university. The situation at home was so bad that I didn't think I could leave my mum, and it didn't look like there was a solution," Juliet says. Her mother was keen for her to go, but it was only the presence of the support worker that made her realise she could leave. "Lucy told me it was important to get an education for my future, and said she would help mum as much as possible."

St Giles Trust is helping rebuild the whole family's resilience. Donations from Guardian readers will help the charity to help more families in similar predicaments.

Eight charities that specialise in turning around the lives of troubled young people will be the beneficiaries of this year's Guardian and Observer charity appeal. Guardian editor-in-chief Alan Rusbridger explains why